@@ -142,13 +142,27 @@ We assess under what conditions European energy inequality is compatible with th
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@@ -142,13 +142,27 @@ We assess under what conditions European energy inequality is compatible with th
# Materials and methods
# Materials and methods
We first decomposed national household final demand expenditure in the Environmentally-Extended Multi-Regional Input-Output (EE-MRIO) model EXIOBASE (version3, industry-by-industry) [@stadler_exiobase_2018], by income quintile, using European household budget survey (HBS) macro-data from EUROSTAT (ref). The EUROSTAT HBS publishes national data on mean consumption expenditure by income quintile (in purchasing power standard (PPS) euro) and the structure of consumption expenditure by income quintile and COICOP consumption category. We mapped the EXIOBASE sectors to one of the COICOP consumption categories (our mapping can be found in the SI), and used the relative shares of each COICOP consumption category between the income quintiles in the HBS to decompose the EXIOBASE national household final demand expenditure per sector by income quintile as well. We then multiplied this income-stratified EXIOBASE national household final demand expenditure by 'total' energy use and carbon intensities per EXIOBASE sector, calculated in EXIOBASE using standard input-output calculations, to estimate national household energy and carbon footprints stratified by income quintile.
## Income-stratified national environmental footprints
The energy footprint is the gross total energy use energy extension in EXIOBASE, which converts final energy consumption in the IEA energy balance data from the territorial to residence principle following SEEA energy accounting (ref - Stadler et al.). The carbon footprint includes CO2, CH4, N2O, SF6, HFCs and PFCs, from combustion, non-combustion, agriculture and waste, but not land-use change. For both environmental footprints, direct energy use and carbon emissions from households is included, with the total split between shelter, transport and manufactured goods using further data from EUROSTAT on this split.
We first decomposed national household final demand expenditure in the Environmentally-Extended Multi-Regional Input-Output (EE-MRIO) model EXIOBASE (version3, industry-by-industry) [@stadler_exiobase_2018], by income quintile, using European household budget survey (HBS) macro-data from EUROSTAT [@eurostat_database_nodate]. The EUROSTAT HBS publishes national data on mean consumption expenditure by income quintile (in purchasing power standard (PPS) euro) and the structure of consumption expenditure by income quintile and COICOP consumption category.
Finally, we aggregated the data of 28 European countries with 5 income groups each into 10 European expenditure groups, to decompose the total European household energy and carbon footprint by European expenditure decile, ranking each national income group according to their mean consumption expenditure in PPS. We call these European expenditure deciles, although only countries with EUROSTAT data from 2005 to 2015 are included, which excludes Italy and Luxembourg, but includes the UK, Norway and Turkey. Data on decarbonization scenarios, especially final energy use, is from the IIASA scenario database [@riahi_shared_2017 @gea_gea_nodate], and work by Grubler et al. (2018) [@grubler_low_2018] and Millward-Hopkins et al. (2020) [@millward-hopkins_providing_2020]. (IEA, Boell?)
We mapped the EXIOBASE sectors to one of the COICOP consumption categories (our mapping can be found in the SI), and used the relative shares of each COICOP consumption category between the income quintiles in the HBS to decompose the EXIOBASE national household final demand expenditure per sector by income quintile as well. We then multiplied this income-stratified EXIOBASE national household final demand expenditure by 'total' energy use and carbon intensities per EXIOBASE sector, calculated in EXIOBASE using standard input-output calculations, to estimate national household energy and carbon footprints stratified by income quintile.
Our unit of analysis through the paper is households normalized by adult equivalent unit, following the income stratified households expenditure data from EUROSTAT. The adult equivalent units from EUROSTAT adjust for household size in different countries and income groups for comparability purposes. When we discuss our household energy and carbon footprints per European expenditure decile in the context of decarbonization scenarios, we adjust total final energy use per capita output from the scenarios to household final energy use per adult equivalent. As inequality measure through the study, we divide the average value of the population in the top decile by that of the bottom decile, a 10:10 ratio. For example, in expenditure, a 10:10 ratio of 5 means that adult equivalents in the top decile spend 5 times more on average than those in the bottom decile.All data and procedures are described in detail in the supplementary information (SI).
## Environmental footprints
The energy footprint is calculated using the 'gross total energy use' energy extension in EXIOBASE, which converts final energy consumption in the IEA energy balance data from the territorial to residence principle following SEEA energy accounting [@stadler_exiobase_2018]. The carbon footprint includes CO2, CH4, N2O, SF6, HFCs and PFCs, from combustion, non-combustion, agriculture and waste, but not land-use change. For both environmental footprints, direct energy use and carbon emissions from households is included, with the total split between shelter, transport and manufactured goods using further data from EUROSTAT on this split.
## European expenditure deciles
Finally, we aggregated the data of 28 European countries with 5 income groups each into 10 European expenditure groups, to decompose the total European household energy and carbon footprint by European expenditure decile, ranking each national income group according to their mean consumption expenditure in PPS. We call these European expenditure deciles, although only countries with EUROSTAT data from 2005 to 2015 are included, which excludes Italy and Luxembourg, but includes the UK, Norway and Turkey. Data on decarbonization scenarios, especially final energy use, is from the IIASA scenario database [@riahi_shared_2017 @gea_gea_nodate], and work by Grubler et al. (2018) [@grubler_low_2018] and Millward-Hopkins et al. (2020) [@millward-hopkins_providing_2020].
## Units of analysis
Our unit of analysis through the study is households per adult equivalent unit. This is the unit of analysis used in the EUROSTAT HBS when normalizing household size between income groups and countries, and we aimed to keep the results of our study within this framework: the first adult in the household is given a weight of 1.0, each adult thereafter 0.5, and each child 0.3 [@eurostat_description_2016].
When we situate our results within decarbonisation scenarios, we adjust the total per capita results from the scenarios, to household per adult equivalence in order to better compare with our environmental footprint estimates. For example, we adjust a total final energy use of 53 GJ per capita from the LED scenario, first by the household share of the total European energy footprint in 2015 (around 0.62, calculated in EXIOBASE), and then the share of total adult equivalents in the total European population in 2015 (also around 0.62, calculated using the EUROSTAT HBS, number of households per country, and population data per country): a total final energy use of 53 GJ/capita is therefore adjusted to a household final energy use of 53 GJ/adult equivalence in Europe ((53 total GJ/capita * 0.62 household share of total footprint)/0.62 adult equivalent share of population = 53 household GJ/adult equivalence).
As inequality measure through the study, we divide the value in the top European expenditure decile by that of the bottom European expenditure decile, a 10:10 ratio. For example, in expenditure, a 10:10 ratio of 5 means that adult equivalents in the top decile spend 5 times more on average than those in the bottom decile. All data and procedures are described in detail in the supplementary information (SI).
